The atorvastatin metabolite pattern in muscle tissue and blood plasma is associated with statin muscle side effects in patients with coronary heart disease; An exploratory case-control study.

Background And Aims: Statin-associated muscle symptoms (SAMS) is a prevalent cause of statin discontinuation. It is challenging and time-consuming for clinicians to assess whether symptoms are caused by the statin or not, and diagnostic biomarkers are requested. Atorvastatin metabolites have been associated with SAMS.

Clinical performance of volumetric finger-prick sampling for the monitoring of tacrolimus, creatinine and haemoglobin in kidney transplant recipients.

Aims: Finger-prick sampling has emerged as an attractive tool for therapeutic drug monitoring and associated diagnostics. We aimed to validate the clinical performance of using two volumetric devices (Capitainer® qDBS and Mitra®) for monitoring tacrolimus, creatinine and haemoglobin in kidney transplant (KTx) recipients. Secondarily, we evaluated potential differences between finger-prick sampling performed by healthcare professionals vs.

Atorvastatin Metabolite Pattern in Skeletal Muscle and Blood from Patients with Coronary Heart Disease and Statin-Associated Muscle Symptoms.

Self-perceived statin-associated muscle symptoms (SAMS) are prevalent, but only a minority is drug-dependent. Diagnostic biomarkers are not yet identified. The local statin exposure in skeletal muscle tissue may correlate to the adverse effects.

Monitoring Simvastatin Adherence in Patients With Coronary Heart Disease: A Proof-of-Concept Study Based on Pharmacokinetic Measurements in Blood Plasma.

Background: Poor statin adherence remains a public health concern associated with adverse outcomes. We evaluated the use of pharmacokinetic measurements to monitor adherence to simvastatin in patients with coronary heart disease (CHD).

Methods: Eighteen patients with CHD taking an evening dose of simvastatin 20 mg (n = 7), 40 mg (n = 5), or 80 mg (n = 6) were examined at steady-state pharmacokinetics.

In vitro assessments predict that CYP3A4 contributes to a greater extent than CYP3A5 to prednisolone clearance.

Because several steroid hormones are metabolized to their respective 6β-hydroxy forms by CYP3A4 and CYP3A5, these isoenzymes have been assumed to metabolize the immunosuppressive drug prednisolone, with conflicting results in the literature with respect to their relative importance. A direct study of the metabolism of prednisolone by microsomal CYP3A4 and CYP3A5 is missing. The aim of this in vitro study was to investigate the relative importance of recombinant CYP3A4 and recombinant CYP3A5 in the metabolism of prednisolone and to compare the extent of formation of 6β-OH-prednisolone by the two enzymes.

Fast and reliable quantification of busulfan in blood plasma using two-channel liquid chromatography tandem mass spectrometry: Validation of assay performance in the presence of drug formulation excipients.

A fast and reliable method based on two-channel liquid chromatography coupled to tandem mass spectrometry was developed and successfully validated for quantification of busulfan. The drug vehicle polyethylene glycol 400 was quantified simultaneously in patient samples. The sample preparation consisted of simple protein precipitation using a mixture of methanol and zinc sulphate containing busulfan-d8 as internal standard.

Prednisolone and Prednisone Pharmacokinetics in Adult Renal Transplant Recipients.

Background: Prednisolone (PL) is a standard component of most immunosuppressive protocols after solid organ transplantation (Tx). Adverse effects are frequent and well known. The aim of this study was to characterize the pharmacokinetics (PKs) of PL and prednisone (PN), including cortisol (CL) and cortisone (CN) profiles, after PL treatment in renal Tx recipients in the early post-Tx phase.

Pharmacodynamic assessment of mycophenolic acid in resting and activated target cell population during the first year after renal transplantation.

Aims: To explore the pharmacodynamics of mycophenolic acid (MPA) through inosine monophosphate dehydrogenase (IMPDH) capacity measurement and purine levels in peripheral blood mononuclear cells (PBMC) longitudinally during the first year after renal transplantation (TX).

Methods: PBMC were isolated from renal recipients 0-4 days prior to and 6-9 days, 5-7 weeks and 1 year after TX (before and 1.5 hours after dose).

Tacrolimus Can Be Reliably Measured With Volumetric Absorptive Capillary Microsampling Throughout the Dose Interval in Renal Transplant Recipients.

Background: Therapeutic drug monitoring is standard practice for the immunosuppressant tacrolimus (Tac). Venous blood sampling at outpatient clinics is time-consuming and impractical with regard to obtaining trough concentrations on clinical visit days. Home-based blood sampling may be patient friendly and pave the way for limited sampling strategies for the prediction of total drug exposure.

Intraperitoneal mitomycin C improves survival compared to cytoreductive surgery alone in an experimental model of high-grade pseudomyxoma peritonei.

Pseudomyxoma peritonei (PMP) is a rare cancer commonly originating from appendiceal neoplasms that presents with mucinous tumor spread in the peritoneal cavity. Patients with PMP are treated with curative intent by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The value of adding HIPEC to CRS has not been proven in randomized trials, and the objective of this study was to investigate the efficacy of intraperitoneal mitomycin C (MMC) and regional hyperthermia as components of this complex treatment.

A Method for Direct Monitoring of Atorvastatin Adherence in Cardiovascular Disease Prevention: Quantification of the Total Exposure to Parent Drug and Major Metabolites Using 2-Channel Chromatography and Tandem Mass Spectrometry.

Background: Low adherence to statin therapy remains a public health concern associated with poor prognosis in cardiovascular disease patients. A feasible method for statin adherence monitoring in clinical practice has yet to be developed. In this article, we describe a novel method designed for the direct monitoring of atorvastatin adherence based on the sum of parent drug and major metabolites in blood samples.

Longitudinal Study of Tacrolimus in Lymphocytes During the First Year After Kidney Transplantation.

Introduction: Tacrolimus (TAC) is an immunosuppressive drug used after organ transplantation. Dosing is adjusted using whole blood (WB-TAC) measurements. Patients within the therapeutic WB-TAC window still experience rejections and adverse effects.

The use of clonidine in elderly patients with delirium; pharmacokinetics and hemodynamic responses.

Background: The Oslo Study of Clonidine in Elderly Patients with Delirium (LUCID) is an RCT investigating the effect of clonidine in medical patients > 65 years with delirium. To assess the dosage regimen and safety measures of this study protocol, we measured the plasma concentrations and hemodynamic effects of clonidine in the first 20 patients.

Methods: Patients were randomised to clonidine (n = 10) or placebo (n = 10).

Determination of Tacrolimus Concentration and Protein Expression of P-Glycoprotein in Single Human Renal Core Biopsies.

Background: Tacrolimus (TAC) is currently the cornerstone of immunosuppressive protocols for renal transplant recipients. Despite therapeutic whole blood monitoring, TAC is associated with nephrotoxicity, and it has been hypothesized that intrarenal accumulation of TAC and/or its metabolites are involved. As TAC is a substrate of P-glycoprotein (P-gp), the expression and activity of this efflux transporter could influence the levels of TAC in renal tissue.

Effects of low-dose clonidine on cardiovascular and autonomic variables in adolescents with chronic fatigue: a randomized controlled trial.

Background: Chronic Fatigue Syndrome (CFS) is a common and disabling condition in adolescence with few treatment options. A central feature of CFS is orthostatic intolerance and abnormal autonomic cardiovascular control characterized by sympathetic predominance. We hypothesized that symptoms as well as the underlying pathophysiology might improve by treatment with the alpha2A-adrenoceptor agonist clonidine.

Disease mechanisms and clonidine treatment in adolescent chronic fatigue syndrome: a combined cross-sectional and randomized clinical trial.

Importance: Chronic fatigue syndrome (CFS) is a disabling condition with unknown disease mechanisms and few treatment options.

Objective: To explore the pathophysiology of CFS and assess clonidine hydrochloride pharmacotherapy in adolescents with CFS by using a hypothesis that patients with CFS have enhanced sympathetic activity and that sympatho-inhibition by clonidine would improve symptoms and function.

Design, Setting, And Participants: Participants were enrolled from a single referral center recruiting nationwide in Norway.

Impact of hyperthermia on pharmacokinetics of intraperitoneal mitomycin C in rats investigated by microdialysis.

Background And Objectives: Patients with peritoneal surface malignancies are treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, commonly using mitomycin C (MMC). The purpose of this study was to investigate impact of hyperthermia on pharmacokinetics of intraperitoneal MMC.

Methods: In 14 athymic nude male rats, microdialysis (MD) probes were implanted in jugular vein (V), hind leg muscle (M) and extraperitoneal space (XP).

Simultaneous quantification of IMPDH activity and purine bases in lymphocytes using LC-MS/MS: assessment of biomarker responses to mycophenolic acid.

Background: The development of biomarkers describing the individual responses to the immunosuppressant mycophenolic acid (MPA) has focused on the target enzyme activity [inosine 5'-monophosphate dehydrogenase (IMPDH)]. An extended strategy is to quantify the metabolic consequences of IMPDH inhibition. The aim of this study was to develop an assay for quantification of IMPDH activity and related purine bases and to provide preliminary data on the behavior of these biomarkers during clinical exposure to MPA.

Activity of neutrophil elastase reflects the progression of acute pancreatitis.

Objective: Neutrophil elastase (NE) concentration is associated with progression of acute pancreatitis (AP), but measuring total NE concentration includes biologically inactive NE. This study aims to investigate the relationship between NE activity and the aetiology and severity of AP and associated organ failure.

Methods: Seventy-five patients admitted to our surgery department with a first episode of AP during 2004-2005 were age- and sex-matched to 20 healthy volunteers (controls).

Mycophenolate pharmacokinetics and inosine monophosphate dehydrogenase activity in liver transplant recipients with an emphasis on therapeutic drug monitoring.

Background: The pharmacokinetics of the immunosuppressant mycophenolic acid (MPA) demonstrates high inter- and intra-patient variability. Variation in the binding of MPA to albumin has been postulated to be an important factor in this variability, and monitoring of free MPA has been suggested to improve therapeutic drug monitoring (TDM) of MPA. Inosine monophosphate dehydrogenase (IMPDH) is the target enzyme for MPA, therefore the IMPDH activity in lymphocytes can serve as a marker of the MPA-specific response.

Clonidine in the treatment of adolescent chronic fatigue syndrome: a pilot study for the NorCAPITAL trial.

Background: This pilot study (ClinicalTrials.gov ID: NCT01507701) assessed the feasibility and safety of clonidine in adolescent chronic fatigue syndrome (CFS). Specifically, we assessed clonidine dosage in relation to a) plasma concentration levels, b) orthostatic cardiovascular responses, and c) possible adverse effects.

Is the SPINK1 variant p.N34S overrepresented in patients with acute pancreatitis?

Objectives: Serine Protease Inhibitor Kazal type 1 (SPINK1) protects against premature intracellular activation of trypsinogen and development of acute pancreatitis. Our aim was to determine the prevalence of SPINK1 mutations (a) in unselected patients with first-time acute pancreatitis and (b) in the Danish background population (c) in a meta-analysis to combine the results with findings in similar investigations worldwide and (d) to evaluate whether patients with SPINK1 mutations had a more severe clinical course.

Methods: A total of 75 consecutive patients admitted to a surgical department with first-time acute pancreatitis were prospectively included.